Electrographic printers and copiers utilizing developer comprising toner, carrier, and other components use a developer mixing apparatus and related processes for mixing the developer and toner used during the printing process. As is well known, the carrier can comprise permanently magnetized ferrite core particles, dispersed in a developer station with toner, whereupon the toner is attracted to and is carried by the ferrite core to an imaging roller for printing on a print medium. The gram weight of the carrier can be approximately 6-8% of the toner, which together comprises the developer. As part of this process, the carrier is intended to be reused and recirculated within the developer station. Certain conditions will cause the carrier to leave the developer station and deposit on the surface of the imaging member. Typically, there exists an electrically biased electrode 103 (the scavenger electrode), as shown in FIG. 1 that urges this carrier off the surface of the imaging member 102 because the biasing induces magnetism in the electrode, whereupon the magnetic force of the development roller 101 will direct the carrier, under gravity, back into the development station substantially in the general direction 105. The scavenger is electrically biased via a combination of high frequency AC imposed on a DC waveform whose function is to provide the motive force for the movement of carrier off of the photoconductor surface. Under the alternating AC field, the carrier rocks free and breaks from the photoconductor surface. The magnetic field from the rotating core magnet then pulls the carrier particle through the slotted scavenger back into the developer station.
There are conditions, however, that result in the release of the carrier from the imaging (photoconductor) member 102, but the trajectory of the carrier is such that it will overshoot the trailing edge of the electrode 103. This can result in carrier accumulating, shown as 204 in FIG. 2, on the outside vertical face of the scavenger electrode 203 or other surfaces, such as on the outer surfaces of the developer station or other surfaces in the imaging engine. Since this carrier is intended to be reused within the developer station, the loss of carrier can result in degradation of the image due to compromised mixing in developer sump. This carrier loss can also accumulate to the point where this carrier mass 204 can make contact with the imaging member 202, thereby physically disrupting the image, resulting in a loss of image quality. The preferred solution for this problem involves cutting slots into the vertical face of the scavenger electrode, such that the scavenged carrier can return to the development station. These slots can create a problem, because toner dust from the interior of the development station can escape 1301, causing increased maintenance of the imaging engine, higher cost of ownership due to the loss of the toner, and degradation of image quality.